Kenneth Clarke is bracing himself for an enforced retirement from the cabinet after Downing Street reacted furiously to his accusation that Theresa May gave a "laughable, childlike" example in criticising the Human Rights Act at this week's Tory party conference.

David Cameron is assessing whether to clear out the bulk of Clarke's Ministry of Justice in a long-awaited reshuffle, after what No 10 regards as a series of blunders. The reshuffle was due in the spring, but there was speculation that the shakeup, which will see the departure of the justice ministers Crispin Blunt and Jonathan Djanogly over separate mistakes, could come as early as next month.

Clarke annoyed Cameron for the second time in a week when he appeared to raise the stakes in his dispute with No 10 and the home secretary over the Human Rights Act. In an interview with the Nottingham Post, the local newspaper in his Rushcliffe constituency, he launched a fresh attack on May over her claim that a man had been able to avoid deportation because he owned a cat.

Clarke, who had mocked May at the Tory conference on Tuesday, said: "I sat and listened to Theresa's speech, and I'll have to be very polite to Theresa when I meet her – but in my opinion she should really address her researchers and advisers very severely for assuring her that a complete nonsense example in her speech was true.

"I'm not going to stand there and say in my private opinion this is a terrible thing and we ought to get rid of the Human Rights Act. It's not only the judges that all get furious when the home secretary makes a parody of a court judgment – our commission, who are helping us form our view on this, are not going to be entertained by laughable, child-like examples being given."

No 10, which supported May's speech and feared the justice secretary was opening a second front, asked Clarke to explain himself. Clarke told them he had given the interview in Manchester, a few hours before Cameron's speech to the conference. The timing of the interview lowered tensions in No 10 because it showed that Clarke had stood by an agreement to pull his punches after Cameron tried to draw a line under the affair by joking in his conference speech that he had asked the justice secretary to read Crime and Punishment twice.

In a statement released at lunchtime, Clarke said: "This is old news from an interview I gave during the conference. I consider this issue closed.

"The prime minister has made the position clear, and I fully support it. There is a problem with deporting foreign prisoners, which I have always agreed with Theresa needs to be addressed. The government's commission on a bill of rights is under way. I do rather regret the colourful language I used at one point in my interview."

No 10 thought the statement would close down the affair. But officials had failed to spot that Clarke and May were due to attend a ministerial meeting on trade. When they were spotted entering No 10, rumours appeared on Twitter that they had been summoned to No 10 for a dressing down. The two ministers made a point of talking in a friendly way as they left No 10 together.

Downing Street regards Clarke's public mocking of May as unacceptable behaviour towards a cabinet colleague. There is particular anger as it was the only divisive moment during the Tory conference.

But Clarke believes he is right on the substance and thinks that May was not speaking for the coalition when she said she would like to see the abolition of the Human Rights Act. Clarke and Nick Clegg are due to receive a copy of a report into the future of the act from a commission after the Liberal Democrats rejected the outright rejection of the act.

The view of the justice secretary was endorsed by Lynne Featherstone, the Lib Dem Home Office minister, who rebuked her boss. In her column in the Hampstead & Highgate Express, she wrote: "There is scope for common ground on dealing with those excesses [in interpreting the act], but outside of tha[t] – the Home Sec's 'personal' desire to see the Human Rights Act go – is just not going to happen under this government."

Friends of Clarke, 71, accept that he may struggle to remain in the cabinet at the next reshuffle. The prime minister will be able to argue that graceful retirement is the right option for the MP who entered parliament when Cameron was three. The Ministry of Justice could see the departure of three of its ministers. Blunt was involved in a row last summer over parties for prisoners. Djanogly has annoyed No 10 over the handling of his business affairs.

But Clarke is adamant he is right in his criticism of May. He cites a statement by the judicial communications office on Tuesday, issued with the full authority of the Lord Chief Justice Lord Judge, which said the Home Office was wrong. The immigration ruling makes clear the judge considered the dying father of the Bolivian student's partner far more important than their joint ownership of Maya the cat in deciding the case. The officially unreported judgment which emerged on Thursdayreveals the unnamed student, aged 33, had been living in a "strong relationship" for four years with his gay partner who is settled in Britain.

The senior immigration judge, JR Devittie, regarded evidence from friends and the partner's brothers as to the quality of relationship as "persuasive and telling".

The original ruling shows that the student overstayed his visa and was issued with a removal notice after being arrested for shoplifting. He was not charged with the offence. The detailed ruling shows the evidence about the cat was only introduced by a witness.

While sources close to May have stressed this reference to the cat, they have not quoted the judge's conclusion that the evidence from friends, relatives and photographs of family occasions had "amply demonstrated" the quality and strength of their relationship. "The evidence shows the appellant is well integrated into the larger family his partner has with his siblings and parents. He attends family functions with his partner and is regarded as a member of the family."

He also rejected the Home Office's contention that they could both simply go and live in Bolivia, pointing out that would not be reasonable given that his partner's father was 'in a condition that he was not expected to recover from' and the family, including the Bolivian student had collectively decided to support him.

The Home Office appealed Devittie's decision claiming it had placed "an inappropriate weight on the Bolivian student having to leave behind not only his partner but also his joint cat." The appeal judge, senior immigration judge Gleeson, does not seem to have taken this seriously and says that the Home Office claim that Devittie had made a mistake in law by applying a policy that had already been withdrawn was more significant.

When the case was heard on 1 December 2008 Gleeson dismissed the appeal saying the immigration authorities had overlooked their own procedures for dealing with unmarried partners of a person present or settled in the UK. But even this judge couldn't resist a parting shot: "The immigration judge's determination is upheld and the cat need no longer fear having to adapt to Bolivian mice."